//
// This file defines routines for folding instructions into constants.
//
-// Also, to supplement the basic VMCore ConstantExpr simplifications,
+// Also, to supplement the basic IR ConstantExpr simplifications,
// this file defines some additional folding routines that can make use of
-// DataLayout information. These functions cannot go in VMCore due to library
+// DataLayout information. These functions cannot go in IR due to library
// dependency issues.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/GlobalVariable.h"
-#include "llvm/Instructions.h"
-#include "llvm/Intrinsics.h"
-#include "llvm/Operator.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/DataLayout.h"
-#include "llvm/Target/TargetLibraryInfo.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Operator.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/FEnv.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/FEnv.h"
+#include "llvm/Target/TargetLibraryInfo.h"
#include <cerrno>
#include <cmath>
using namespace llvm;
// Constant Folding internal helper functions
//===----------------------------------------------------------------------===//
-/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with
+/// FoldBitCast - Constant fold bitcast, symbolically evaluating it with
/// DataLayout. This always returns a non-null constant, but it may be a
/// ConstantExpr if unfoldable.
static Constant *FoldBitCast(Constant *C, Type *DestTy,
// Handle a vector->integer cast.
if (IntegerType *IT = dyn_cast<IntegerType>(DestTy)) {
- ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(C);
- if (CDV == 0)
+ VectorType *VTy = dyn_cast<VectorType>(C->getType());
+ if (VTy == 0)
return ConstantExpr::getBitCast(C, DestTy);
- unsigned NumSrcElts = CDV->getType()->getNumElements();
-
- Type *SrcEltTy = CDV->getType()->getElementType();
-
+ unsigned NumSrcElts = VTy->getNumElements();
+ Type *SrcEltTy = VTy->getElementType();
+
// If the vector is a vector of floating point, convert it to vector of int
// to simplify things.
if (SrcEltTy->isFloatingPointTy()) {
unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
Type *SrcIVTy =
VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElts);
- // Ask VMCore to do the conversion now that #elts line up.
+ // Ask IR to do the conversion now that #elts line up.
C = ConstantExpr::getBitCast(C, SrcIVTy);
- CDV = cast<ConstantDataVector>(C);
}
-
+
+ ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(C);
+ if (CDV == 0)
+ return ConstantExpr::getBitCast(C, DestTy);
+
// Now that we know that the input value is a vector of integers, just shift
// and insert them into our result.
unsigned BitShift = TD.getTypeAllocSizeInBits(SrcEltTy);
else
Result |= CDV->getElementAsInteger(i);
}
-
+
return ConstantInt::get(IT, Result);
}
-
+
// The code below only handles casts to vectors currently.
VectorType *DestVTy = dyn_cast<VectorType>(DestTy);
if (DestVTy == 0)
return ConstantExpr::getBitCast(C, DestTy);
-
+
// If this is a scalar -> vector cast, convert the input into a <1 x scalar>
// vector so the code below can handle it uniformly.
if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) {
Constant *Ops = C; // don't take the address of C!
return FoldBitCast(ConstantVector::get(Ops), DestTy, TD);
}
-
+
// If this is a bitcast from constant vector -> vector, fold it.
if (!isa<ConstantDataVector>(C) && !isa<ConstantVector>(C))
return ConstantExpr::getBitCast(C, DestTy);
-
- // If the element types match, VMCore can fold it.
+
+ // If the element types match, IR can fold it.
unsigned NumDstElt = DestVTy->getNumElements();
unsigned NumSrcElt = C->getType()->getVectorNumElements();
if (NumDstElt == NumSrcElt)
return ConstantExpr::getBitCast(C, DestTy);
-
+
Type *SrcEltTy = C->getType()->getVectorElementType();
Type *DstEltTy = DestVTy->getElementType();
-
- // Otherwise, we're changing the number of elements in a vector, which
+
+ // Otherwise, we're changing the number of elements in a vector, which
// requires endianness information to do the right thing. For example,
// bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
// folds to (little endian):
// <4 x i32> <i32 0, i32 0, i32 1, i32 0>
// and to (big endian):
// <4 x i32> <i32 0, i32 0, i32 0, i32 1>
-
+
// First thing is first. We only want to think about integer here, so if
// we have something in FP form, recast it as integer.
if (DstEltTy->isFloatingPointTy()) {
VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumDstElt);
// Recursively handle this integer conversion, if possible.
C = FoldBitCast(C, DestIVTy, TD);
-
- // Finally, VMCore can handle this now that #elts line up.
+
+ // Finally, IR can handle this now that #elts line up.
return ConstantExpr::getBitCast(C, DestTy);
}
-
+
// Okay, we know the destination is integer, if the input is FP, convert
// it to integer first.
if (SrcEltTy->isFloatingPointTy()) {
unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
Type *SrcIVTy =
VectorType::get(IntegerType::get(C->getContext(), FPWidth), NumSrcElt);
- // Ask VMCore to do the conversion now that #elts line up.
+ // Ask IR to do the conversion now that #elts line up.
C = ConstantExpr::getBitCast(C, SrcIVTy);
- // If VMCore wasn't able to fold it, bail out.
+ // If IR wasn't able to fold it, bail out.
if (!isa<ConstantVector>(C) && // FIXME: Remove ConstantVector.
!isa<ConstantDataVector>(C))
return C;
}
-
+
// Now we know that the input and output vectors are both integer vectors
// of the same size, and that their #elements is not the same. Do the
// conversion here, which depends on whether the input or output has
// more elements.
bool isLittleEndian = TD.isLittleEndian();
-
+
SmallVector<Constant*, 32> Result;
if (NumDstElt < NumSrcElt) {
// Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
Constant *Src =dyn_cast<ConstantInt>(C->getAggregateElement(SrcElt++));
if (!Src) // Reject constantexpr elements.
return ConstantExpr::getBitCast(C, DestTy);
-
+
// Zero extend the element to the right size.
Src = ConstantExpr::getZExt(Src, Elt->getType());
-
+
// Shift it to the right place, depending on endianness.
- Src = ConstantExpr::getShl(Src,
+ Src = ConstantExpr::getShl(Src,
ConstantInt::get(Src->getType(), ShiftAmt));
ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;
-
+
// Mix it in.
Elt = ConstantExpr::getOr(Elt, Src);
}
}
return ConstantVector::get(Result);
}
-
+
// Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
unsigned Ratio = NumDstElt/NumSrcElt;
unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits();
-
+
// Loop over each source value, expanding into multiple results.
for (unsigned i = 0; i != NumSrcElt; ++i) {
Constant *Src = dyn_cast<ConstantInt>(C->getAggregateElement(i));
if (!Src) // Reject constantexpr elements.
return ConstantExpr::getBitCast(C, DestTy);
-
+
unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
for (unsigned j = 0; j != Ratio; ++j) {
// Shift the piece of the value into the right place, depending on
// endianness.
- Constant *Elt = ConstantExpr::getLShr(Src,
+ Constant *Elt = ConstantExpr::getLShr(Src,
ConstantInt::get(Src->getType(), ShiftAmt));
ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
-
+
// Truncate and remember this piece.
Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
}
}
-
+
return ConstantVector::get(Result);
}
/// from a global, return the global and the constant. Because of
/// constantexprs, this function is recursive.
static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
- int64_t &Offset, const DataLayout &TD) {
+ APInt &Offset, const DataLayout &TD) {
// Trivial case, constant is the global.
if ((GV = dyn_cast<GlobalValue>(C))) {
- Offset = 0;
+ Offset.clearAllBits();
return true;
}
-
+
// Otherwise, if this isn't a constant expr, bail out.
ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
if (!CE) return false;
-
+
// Look through ptr->int and ptr->ptr casts.
if (CE->getOpcode() == Instruction::PtrToInt ||
CE->getOpcode() == Instruction::BitCast)
return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
-
- // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
- if (CE->getOpcode() == Instruction::GetElementPtr) {
- // Cannot compute this if the element type of the pointer is missing size
- // info.
- if (!cast<PointerType>(CE->getOperand(0)->getType())
- ->getElementType()->isSized())
- return false;
-
+
+ // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(CE)) {
// If the base isn't a global+constant, we aren't either.
if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD))
return false;
-
+
// Otherwise, add any offset that our operands provide.
- gep_type_iterator GTI = gep_type_begin(CE);
- for (User::const_op_iterator i = CE->op_begin() + 1, e = CE->op_end();
- i != e; ++i, ++GTI) {
- ConstantInt *CI = dyn_cast<ConstantInt>(*i);
- if (!CI) return false; // Index isn't a simple constant?
- if (CI->isZero()) continue; // Not adding anything.
-
- if (StructType *ST = dyn_cast<StructType>(*GTI)) {
- // N = N + Offset
- Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue());
- } else {
- SequentialType *SQT = cast<SequentialType>(*GTI);
- Offset += TD.getTypeAllocSize(SQT->getElementType())*CI->getSExtValue();
- }
- }
- return true;
+ return GEP->accumulateConstantOffset(TD, Offset);
}
-
+
return false;
}
const DataLayout &TD) {
assert(ByteOffset <= TD.getTypeAllocSize(C->getType()) &&
"Out of range access");
-
+
// If this element is zero or undefined, we can just return since *CurPtr is
// zero initialized.
if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
return true;
-
+
if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
if (CI->getBitWidth() > 64 ||
(CI->getBitWidth() & 7) != 0)
return false;
-
+
uint64_t Val = CI->getZExtValue();
unsigned IntBytes = unsigned(CI->getBitWidth()/8);
-
+
for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
- CurPtr[i] = (unsigned char)(Val >> (ByteOffset * 8));
+ int n = ByteOffset;
+ if (!TD.isLittleEndian())
+ n = IntBytes - n - 1;
+ CurPtr[i] = (unsigned char)(Val >> (n * 8));
++ByteOffset;
}
return true;
}
-
+
if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
if (CFP->getType()->isDoubleTy()) {
C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), TD);
C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), TD);
return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
}
+ if (CFP->getType()->isHalfTy()){
+ C = FoldBitCast(C, Type::getInt16Ty(C->getContext()), TD);
+ return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, TD);
+ }
return false;
}
-
+
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
const StructLayout *SL = TD.getStructLayout(CS->getType());
unsigned Index = SL->getElementContainingOffset(ByteOffset);
uint64_t CurEltOffset = SL->getElementOffset(Index);
ByteOffset -= CurEltOffset;
-
+
while (1) {
// If the element access is to the element itself and not to tail padding,
// read the bytes from the element.
!ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr,
BytesLeft, TD))
return false;
-
+
++Index;
-
+
// Check to see if we read from the last struct element, if so we're done.
if (Index == CS->getType()->getNumElements())
return true;
}
return true;
}
-
+
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
if (CE->getOpcode() == Instruction::IntToPtr &&
- CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getContext()))
- return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
+ CE->getOperand(0)->getType() == TD.getIntPtrType(CE->getContext()))
+ return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
BytesLeft, TD);
}
const DataLayout &TD) {
Type *LoadTy = cast<PointerType>(C->getType())->getElementType();
IntegerType *IntType = dyn_cast<IntegerType>(LoadTy);
-
+
// If this isn't an integer load we can't fold it directly.
if (!IntType) {
// If this is a float/double load, we can try folding it as an int32/64 load
// that address spaces don't matter here since we're not going to result in
// an actual new load.
Type *MapTy;
- if (LoadTy->isFloatTy())
+ if (LoadTy->isHalfTy())
+ MapTy = Type::getInt16PtrTy(C->getContext());
+ else if (LoadTy->isFloatTy())
MapTy = Type::getInt32PtrTy(C->getContext());
else if (LoadTy->isDoubleTy())
MapTy = Type::getInt64PtrTy(C->getContext());
return FoldBitCast(Res, LoadTy, TD);
return 0;
}
-
+
unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
if (BytesLoaded > 32 || BytesLoaded == 0) return 0;
-
+
GlobalValue *GVal;
- int64_t Offset;
+ APInt Offset(TD.getPointerSizeInBits(), 0);
if (!IsConstantOffsetFromGlobal(C, GVal, Offset, TD))
return 0;
-
+
GlobalVariable *GV = dyn_cast<GlobalVariable>(GVal);
if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
!GV->getInitializer()->getType()->isSized())
// If we're loading off the beginning of the global, some bytes may be valid,
// but we don't try to handle this.
- if (Offset < 0) return 0;
-
+ if (Offset.isNegative()) return 0;
+
// If we're not accessing anything in this constant, the result is undefined.
- if (uint64_t(Offset) >= TD.getTypeAllocSize(GV->getInitializer()->getType()))
+ if (Offset.getZExtValue() >=
+ TD.getTypeAllocSize(GV->getInitializer()->getType()))
return UndefValue::get(IntType);
-
+
unsigned char RawBytes[32] = {0};
- if (!ReadDataFromGlobal(GV->getInitializer(), Offset, RawBytes,
+ if (!ReadDataFromGlobal(GV->getInitializer(), Offset.getZExtValue(), RawBytes,
BytesLoaded, TD))
return 0;
- APInt ResultVal = APInt(IntType->getBitWidth(), RawBytes[BytesLoaded-1]);
- for (unsigned i = 1; i != BytesLoaded; ++i) {
- ResultVal <<= 8;
- ResultVal |= RawBytes[BytesLoaded-1-i];
+ APInt ResultVal = APInt(IntType->getBitWidth(), 0);
+ if (TD.isLittleEndian()) {
+ ResultVal = RawBytes[BytesLoaded - 1];
+ for (unsigned i = 1; i != BytesLoaded; ++i) {
+ ResultVal <<= 8;
+ ResultVal |= RawBytes[BytesLoaded-1-i];
+ }
+ } else {
+ ResultVal = RawBytes[0];
+ for (unsigned i = 1; i != BytesLoaded; ++i) {
+ ResultVal <<= 8;
+ ResultVal |= RawBytes[i];
+ }
}
return ConstantInt::get(IntType->getContext(), ResultVal);
// If the loaded value isn't a constant expr, we can't handle it.
ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
if (!CE) return 0;
-
+
if (CE->getOpcode() == Instruction::GetElementPtr) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
if (GV->isConstant() && GV->hasDefinitiveInitializer())
- if (Constant *V =
+ if (Constant *V =
ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
return V;
}
-
+
// Instead of loading constant c string, use corresponding integer value
// directly if string length is small enough.
StringRef Str;
SingleChar = 0;
StrVal = (StrVal << 8) | SingleChar;
}
-
+
Constant *Res = ConstantInt::get(CE->getContext(), StrVal);
if (Ty->isFloatingPointTy())
Res = ConstantExpr::getBitCast(Res, Ty);
return Res;
}
}
-
+
// If this load comes from anywhere in a constant global, and if the global
// is all undef or zero, we know what it loads.
if (GlobalVariable *GV =
return UndefValue::get(ResTy);
}
}
-
- // Try hard to fold loads from bitcasted strange and non-type-safe things. We
- // currently don't do any of this for big endian systems. It can be
- // generalized in the future if someone is interested.
- if (TD && TD->isLittleEndian())
+
+ // Try hard to fold loads from bitcasted strange and non-type-safe things.
+ if (TD)
return FoldReinterpretLoadFromConstPtr(CE, *TD);
return 0;
}
static Constant *ConstantFoldLoadInst(const LoadInst *LI, const DataLayout *TD){
if (LI->isVolatile()) return 0;
-
+
if (Constant *C = dyn_cast<Constant>(LI->getOperand(0)))
return ConstantFoldLoadFromConstPtr(C, TD);
/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
/// Attempt to symbolically evaluate the result of a binary operator merging
-/// these together. If target data info is available, it is provided as TD,
-/// otherwise TD is null.
+/// these together. If target data info is available, it is provided as DL,
+/// otherwise DL is null.
static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
- Constant *Op1, const DataLayout *TD){
+ Constant *Op1, const DataLayout *DL){
// SROA
-
+
// Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
// Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
// bits.
-
-
+
+
+ if (Opc == Instruction::And && DL) {
+ unsigned BitWidth = DL->getTypeSizeInBits(Op0->getType()->getScalarType());
+ APInt KnownZero0(BitWidth, 0), KnownOne0(BitWidth, 0);
+ APInt KnownZero1(BitWidth, 0), KnownOne1(BitWidth, 0);
+ ComputeMaskedBits(Op0, KnownZero0, KnownOne0, DL);
+ ComputeMaskedBits(Op1, KnownZero1, KnownOne1, DL);
+ if ((KnownOne1 | KnownZero0).isAllOnesValue()) {
+ // All the bits of Op0 that the 'and' could be masking are already zero.
+ return Op0;
+ }
+ if ((KnownOne0 | KnownZero1).isAllOnesValue()) {
+ // All the bits of Op1 that the 'and' could be masking are already zero.
+ return Op1;
+ }
+
+ APInt KnownZero = KnownZero0 | KnownZero1;
+ APInt KnownOne = KnownOne0 & KnownOne1;
+ if ((KnownZero | KnownOne).isAllOnesValue()) {
+ return ConstantInt::get(Op0->getType(), KnownOne);
+ }
+ }
+
// If the constant expr is something like &A[123] - &A[4].f, fold this into a
// constant. This happens frequently when iterating over a global array.
- if (Opc == Instruction::Sub && TD) {
+ if (Opc == Instruction::Sub && DL) {
GlobalValue *GV1, *GV2;
- int64_t Offs1, Offs2;
-
- if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD))
- if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) &&
+ unsigned PtrSize = DL->getPointerSizeInBits();
+ unsigned OpSize = DL->getTypeSizeInBits(Op0->getType());
+ APInt Offs1(PtrSize, 0), Offs2(PtrSize, 0);
+
+ if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *DL))
+ if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *DL) &&
GV1 == GV2) {
// (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
- return ConstantInt::get(Op0->getType(), Offs1-Offs2);
+ // PtrToInt may change the bitwidth so we have convert to the right size
+ // first.
+ return ConstantInt::get(Op0->getType(), Offs1.zextOrTrunc(OpSize) -
+ Offs2.zextOrTrunc(OpSize));
}
}
-
+
return 0;
}
if (!TD || !cast<PointerType>(Ptr->getType())->getElementType()->isSized() ||
!Ptr->getType()->isPointerTy())
return 0;
-
+
Type *IntPtrTy = TD->getIntPtrType(Ptr->getContext());
// If this is a constant expr gep that is effectively computing an
// "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
for (unsigned i = 1, e = Ops.size(); i != e; ++i)
if (!isa<ConstantInt>(Ops[i])) {
-
+
// If this is "gep i8* Ptr, (sub 0, V)", fold this as:
// "inttoptr (sub (ptrtoint Ptr), V)"
if (Ops.size() == 2 &&
// The only pointer indexing we'll do is on the first index of the GEP.
if (!NewIdxs.empty())
break;
-
+
// Only handle pointers to sized types, not pointers to functions.
if (!ATy->getElementType()->isSized())
return 0;
}
-
+
// Determine which element of the array the offset points into.
APInt ElemSize(BitWidth, TD->getTypeAllocSize(ATy->getElementType()));
IntegerType *IntPtrTy = TD->getIntPtrType(Ty->getContext());
if (const CmpInst *CI = dyn_cast<CmpInst>(I))
return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
TD, TLI);
-
+
if (const LoadInst *LI = dyn_cast<LoadInst>(I))
return ConstantFoldLoadInst(LI, TD);
return ConstantFoldInstOperands(I->getOpcode(), I->getType(), Ops, TD, TLI);
}
-/// ConstantFoldConstantExpression - Attempt to fold the constant expression
-/// using the specified DataLayout. If successful, the constant result is
-/// result is returned, if not, null is returned.
-Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
- const DataLayout *TD,
- const TargetLibraryInfo *TLI) {
- SmallVector<Constant*, 8> Ops;
- for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end();
- i != e; ++i) {
+static Constant *
+ConstantFoldConstantExpressionImpl(const ConstantExpr *CE, const DataLayout *TD,
+ const TargetLibraryInfo *TLI,
+ SmallPtrSet<ConstantExpr *, 4> &FoldedOps) {
+ SmallVector<Constant *, 8> Ops;
+ for (User::const_op_iterator i = CE->op_begin(), e = CE->op_end(); i != e;
+ ++i) {
Constant *NewC = cast<Constant>(*i);
- // Recursively fold the ConstantExpr's operands.
- if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC))
- NewC = ConstantFoldConstantExpression(NewCE, TD, TLI);
+ // Recursively fold the ConstantExpr's operands. If we have already folded
+ // a ConstantExpr, we don't have to process it again.
+ if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(NewC)) {
+ if (FoldedOps.insert(NewCE))
+ NewC = ConstantFoldConstantExpressionImpl(NewCE, TD, TLI, FoldedOps);
+ }
Ops.push_back(NewC);
}
return ConstantFoldInstOperands(CE->getOpcode(), CE->getType(), Ops, TD, TLI);
}
+/// ConstantFoldConstantExpression - Attempt to fold the constant expression
+/// using the specified DataLayout. If successful, the constant result is
+/// result is returned, if not, null is returned.
+Constant *llvm::ConstantFoldConstantExpression(const ConstantExpr *CE,
+ const DataLayout *TD,
+ const TargetLibraryInfo *TLI) {
+ SmallPtrSet<ConstantExpr *, 4> FoldedOps;
+ return ConstantFoldConstantExpressionImpl(CE, TD, TLI, FoldedOps);
+}
+
/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
/// specified opcode and operands. If successful, the constant result is
/// returned, if not, null is returned. Note that this function can fail when
/// information, due to only being passed an opcode and operands. Constant
/// folding using this function strips this information.
///
-Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
+Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, Type *DestTy,
ArrayRef<Constant *> Ops,
const DataLayout *TD,
- const TargetLibraryInfo *TLI) {
+ const TargetLibraryInfo *TLI) {
// Handle easy binops first.
if (Instruction::isBinaryOp(Opcode)) {
if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1]))
if (Constant *C = SymbolicallyEvaluateBinop(Opcode, Ops[0], Ops[1], TD))
return C;
-
+
return ConstantExpr::get(Opcode, Ops[0], Ops[1]);
}
-
+
switch (Opcode) {
default: return 0;
case Instruction::ICmp:
Constant *Input = CE->getOperand(0);
unsigned InWidth = Input->getType()->getScalarSizeInBits();
if (TD->getPointerSizeInBits() < InWidth) {
- Constant *Mask =
+ Constant *Mask =
ConstantInt::get(CE->getContext(), APInt::getLowBitsSet(InWidth,
TD->getPointerSizeInBits()));
Input = ConstantExpr::getAnd(Input, Mask);
return C;
if (Constant *C = SymbolicallyEvaluateGEP(Ops, DestTy, TD, TLI))
return C;
-
+
return ConstantExpr::getGetElementPtr(Ops[0], Ops.slice(1));
}
}
/// returns a constant expression of the specified operands.
///
Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate,
- Constant *Ops0, Constant *Ops1,
+ Constant *Ops0, Constant *Ops1,
const DataLayout *TD,
const TargetLibraryInfo *TLI) {
// fold: icmp (inttoptr x), null -> icmp x, 0
Constant *Null = Constant::getNullValue(C->getType());
return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI);
}
-
+
// Only do this transformation if the int is intptrty in size, otherwise
// there is a truncation or extension that we aren't modeling.
- if (CE0->getOpcode() == Instruction::PtrToInt &&
+ if (CE0->getOpcode() == Instruction::PtrToInt &&
CE0->getType() == IntPtrTy) {
Constant *C = CE0->getOperand(0);
Constant *Null = Constant::getNullValue(C->getType());
return ConstantFoldCompareInstOperands(Predicate, C, Null, TD, TLI);
}
}
-
+
if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
if (TD && CE0->getOpcode() == CE1->getOpcode()) {
Type *IntPtrTy = TD->getIntPtrType(CE0->getContext());
CE1->getOperand(0), TD, TLI);
}
}
-
+
// icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0)
// icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0)
if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) &&
CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) {
- Constant *LHS =
+ Constant *LHS =
ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(0), Ops1,
TD, TLI);
- Constant *RHS =
+ Constant *RHS =
ConstantFoldCompareInstOperands(Predicate, CE0->getOperand(1), Ops1,
TD, TLI);
- unsigned OpC =
+ unsigned OpC =
Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
Constant *Ops[] = { LHS, RHS };
return ConstantFoldInstOperands(OpC, LHS->getType(), Ops, TD, TLI);
}
}
-
+
return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
}
/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a
/// getelementptr constantexpr, return the constant value being addressed by the
/// constant expression, or null if something is funny and we can't decide.
-Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
+Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C,
ConstantExpr *CE) {
if (!CE->getOperand(1)->isNullValue())
return 0; // Do not allow stepping over the value!
bool
llvm::canConstantFoldCallTo(const Function *F) {
switch (F->getIntrinsicID()) {
+ case Intrinsic::fabs:
+ case Intrinsic::log:
+ case Intrinsic::log2:
+ case Intrinsic::log10:
+ case Intrinsic::exp:
+ case Intrinsic::exp2:
+ case Intrinsic::floor:
case Intrinsic::sqrt:
case Intrinsic::pow:
case Intrinsic::powi:
if (!F->hasName()) return false;
StringRef Name = F->getName();
-
+
// In these cases, the check of the length is required. We don't want to
// return true for a name like "cos\0blah" which strcmp would return equal to
// "cos", but has length 8.
switch (Name[0]) {
default: return false;
case 'a':
- return Name == "acos" || Name == "asin" ||
- Name == "atan" || Name == "atan2";
+ return Name == "acos" || Name == "asin" || Name == "atan" || Name =="atan2";
case 'c':
return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh";
case 'e':
}
}
-static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
+static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
Type *Ty) {
sys::llvm_fenv_clearexcept();
V = NativeFP(V);
sys::llvm_fenv_clearexcept();
return 0;
}
-
+
+ if (Ty->isHalfTy()) {
+ APFloat APF(V);
+ bool unused;
+ APF.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &unused);
+ return ConstantFP::get(Ty->getContext(), APF);
+ }
if (Ty->isFloatTy())
return ConstantFP::get(Ty->getContext(), APFloat((float)V));
if (Ty->isDoubleTy())
return ConstantFP::get(Ty->getContext(), APFloat(V));
- llvm_unreachable("Can only constant fold float/double");
+ llvm_unreachable("Can only constant fold half/float/double");
}
static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
sys::llvm_fenv_clearexcept();
return 0;
}
-
+
+ if (Ty->isHalfTy()) {
+ APFloat APF(V);
+ bool unused;
+ APF.convert(APFloat::IEEEhalf, APFloat::rmNearestTiesToEven, &unused);
+ return ConstantFP::get(Ty->getContext(), APF);
+ }
if (Ty->isFloatTy())
return ConstantFP::get(Ty->getContext(), APFloat((float)V));
if (Ty->isDoubleTy())
return ConstantFP::get(Ty->getContext(), APFloat(V));
- llvm_unreachable("Can only constant fold float/double");
+ llvm_unreachable("Can only constant fold half/float/double");
}
/// ConstantFoldConvertToInt - Attempt to an SSE floating point to integer
if (!TLI)
return 0;
- if (!Ty->isFloatTy() && !Ty->isDoubleTy())
+ if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
return 0;
/// We only fold functions with finite arguments. Folding NaN and inf is
/// the host native double versions. Float versions are not called
/// directly but for all these it is true (float)(f((double)arg)) ==
/// f(arg). Long double not supported yet.
- double V = Ty->isFloatTy() ? (double)Op->getValueAPF().convertToFloat() :
- Op->getValueAPF().convertToDouble();
+ double V;
+ if (Ty->isFloatTy())
+ V = Op->getValueAPF().convertToFloat();
+ else if (Ty->isDoubleTy())
+ V = Op->getValueAPF().convertToDouble();
+ else {
+ bool unused;
+ APFloat APF = Op->getValueAPF();
+ APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
+ V = APF.convertToDouble();
+ }
+
+ switch (F->getIntrinsicID()) {
+ default: break;
+ case Intrinsic::fabs:
+ return ConstantFoldFP(fabs, V, Ty);
+#if HAVE_LOG2
+ case Intrinsic::log2:
+ return ConstantFoldFP(log2, V, Ty);
+#endif
+#if HAVE_LOG
+ case Intrinsic::log:
+ return ConstantFoldFP(log, V, Ty);
+#endif
+#if HAVE_LOG10
+ case Intrinsic::log10:
+ return ConstantFoldFP(log10, V, Ty);
+#endif
+#if HAVE_EXP
+ case Intrinsic::exp:
+ return ConstantFoldFP(exp, V, Ty);
+#endif
+#if HAVE_EXP2
+ case Intrinsic::exp2:
+ return ConstantFoldFP(exp2, V, Ty);
+#endif
+ case Intrinsic::floor:
+ return ConstantFoldFP(floor, V, Ty);
+ }
+
switch (Name[0]) {
case 'a':
if (Name == "acos" && TLI->has(LibFunc::acos))
case 'e':
if (Name == "exp" && TLI->has(LibFunc::exp))
return ConstantFoldFP(exp, V, Ty);
-
+
if (Name == "exp2" && TLI->has(LibFunc::exp2)) {
// Constant fold exp2(x) as pow(2,x) in case the host doesn't have a
// C99 library.
else if (Name == "log10" && V > 0 && TLI->has(LibFunc::log10))
return ConstantFoldFP(log10, V, Ty);
else if (F->getIntrinsicID() == Intrinsic::sqrt &&
- (Ty->isFloatTy() || Ty->isDoubleTy())) {
+ (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy())) {
if (V >= -0.0)
return ConstantFoldFP(sqrt, V, Ty);
else // Undefined
case Intrinsic::ctpop:
return ConstantInt::get(Ty, Op->getValue().countPopulation());
case Intrinsic::convert_from_fp16: {
- APFloat Val(Op->getValue());
+ APFloat Val(APFloat::IEEEhalf, Op->getValue());
bool lost = false;
APFloat::opStatus status =
}
// Support ConstantVector in case we have an Undef in the top.
- if (isa<ConstantVector>(Operands[0]) ||
+ if (isa<ConstantVector>(Operands[0]) ||
isa<ConstantDataVector>(Operands[0])) {
Constant *Op = cast<Constant>(Operands[0]);
switch (F->getIntrinsicID()) {
case Intrinsic::x86_sse2_cvttsd2si64:
if (ConstantFP *FPOp =
dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
- return ConstantFoldConvertToInt(FPOp->getValueAPF(),
+ return ConstantFoldConvertToInt(FPOp->getValueAPF(),
/*roundTowardZero=*/true, Ty);
}
}
-
+
if (isa<UndefValue>(Operands[0])) {
if (F->getIntrinsicID() == Intrinsic::bswap)
return Operands[0];
if (Operands.size() == 2) {
if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
- if (!Ty->isFloatTy() && !Ty->isDoubleTy())
+ if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
return 0;
- double Op1V = Ty->isFloatTy() ?
- (double)Op1->getValueAPF().convertToFloat() :
- Op1->getValueAPF().convertToDouble();
+ double Op1V;
+ if (Ty->isFloatTy())
+ Op1V = Op1->getValueAPF().convertToFloat();
+ else if (Ty->isDoubleTy())
+ Op1V = Op1->getValueAPF().convertToDouble();
+ else {
+ bool unused;
+ APFloat APF = Op1->getValueAPF();
+ APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
+ Op1V = APF.convertToDouble();
+ }
+
if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
if (Op2->getType() != Op1->getType())
return 0;
- double Op2V = Ty->isFloatTy() ?
- (double)Op2->getValueAPF().convertToFloat():
- Op2->getValueAPF().convertToDouble();
+ double Op2V;
+ if (Ty->isFloatTy())
+ Op2V = Op2->getValueAPF().convertToFloat();
+ else if (Ty->isDoubleTy())
+ Op2V = Op2->getValueAPF().convertToDouble();
+ else {
+ bool unused;
+ APFloat APF = Op2->getValueAPF();
+ APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, &unused);
+ Op2V = APF.convertToDouble();
+ }
if (F->getIntrinsicID() == Intrinsic::pow) {
return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
if (Name == "atan2" && TLI->has(LibFunc::atan2))
return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
} else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
+ if (F->getIntrinsicID() == Intrinsic::powi && Ty->isHalfTy())
+ return ConstantFP::get(F->getContext(),
+ APFloat((float)std::pow((float)Op1V,
+ (int)Op2C->getZExtValue())));
if (F->getIntrinsicID() == Intrinsic::powi && Ty->isFloatTy())
return ConstantFP::get(F->getContext(),
APFloat((float)std::pow((float)Op1V,
}
return 0;
}
-
+
if (ConstantInt *Op1 = dyn_cast<ConstantInt>(Operands[0])) {
if (ConstantInt *Op2 = dyn_cast<ConstantInt>(Operands[1])) {
switch (F->getIntrinsicID()) {
return ConstantStruct::get(cast<StructType>(F->getReturnType()), Ops);
}
case Intrinsic::cttz:
- // FIXME: This should check for Op2 == 1, and become unreachable if
- // Op1 == 0.
+ if (Op2->isOne() && Op1->isZero()) // cttz(0, 1) is undef.
+ return UndefValue::get(Ty);
return ConstantInt::get(Ty, Op1->getValue().countTrailingZeros());
case Intrinsic::ctlz:
- // FIXME: This should check for Op2 == 1, and become unreachable if
- // Op1 == 0.
+ if (Op2->isOne() && Op1->isZero()) // ctlz(0, 1) is undef.
+ return UndefValue::get(Ty);
return ConstantInt::get(Ty, Op1->getValue().countLeadingZeros());
}
}
-
+
return 0;
}
return 0;
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